Bicycle-pump.



Patented Apr. I0, |900. J. H. ROBINSON.

lcYcLE PUMP.

(Applicgtion led Aug. 43, 1899.)

me Nomus PETERS so. Puma-LINO.. wAsulNnTou. D. c.

NrTED 'STATES PATENT Oie-rien.V

JOI-IN I-I. ROBINSON, OF WASHINGTON, DISTRICT OF COLUMBIA.

BICYCLE-PUMP.

SPECIFIoATIoN forming part of Letters Patent No. 647,329, dated April1o, 1903.

Application led August 3, 1 89 9.

To @ZZ whom it may concern,.-

Be it known that I, JOHN H. ROBINSON, of Washington city, in theDistrict of Columbia, have invented a new and Improved Bicycle- Pump, ofwhich the following is a specification.

The ordinary hand or foot pump used for inflating bicycle -tiresrequires the attachment of a flexible tube as a means for connecting itwith the nipple on the wheel-tire. The pump also lacks power andefficiency and requires the application of great force to operate it,besides having other objections which I seek to remove.

I have devised a pump that may be applied and operated without theflexible connectingtube above referred to, it being adapted to beapplied directly to the tire-nipple, so that cost, labor, and time areeconomized. It is also adapted to be operated with less force and withgreater efficiency than pumps of the usual construction.

The several features of novelty and superiority are as hereinafterdescribed, reference being had to the accompanying drawings, in which`Figure 1 is a view illustrating the pump as applied in practice. Fig. 2is a central longitudinal section of my preferred form of pump. Fig. 3is an enlarged cross-section on line 3 3 of Fig. 2. Figa is aperspective view of the end plug for the barrel. Fig. 5 includes twoviews of the pistonproper. Fig. 6 is a longitudinal section of amodified or valved form of pump. Fig. 7 is a central longitudinalsection of the modified form of piston-expander. Fig; 8 is an enlargedcentral longitudinal section of the modified valved form of end plug forthe barrel. Fig. 9 is a perspective view of the metal cage or holder forthe valves employed in the modified form of pump.

I will first describe the preferred form of my invention, Figs. l to 5.

The body or `barrel 1 of the pump has a much greater length and lessdiameter than that of the ordinary one. The piston-tube 2 is fittedloosely in the barrel 1 and has about the same length as the latter. Anelastic shouldered plug 3 isinserted in its upper end, and a rubbersleeve 4 encireles it, as shown. The said plug serves as .a cushion forthe sensi No. 726,026. ci@ maar.)

hand of the operator, and the annular sleeve, striking upon the barrel lat each down stroke', relieves the shock of impact. It also enables theoperator to obtain a better handheld or grip on the piston-tube 2. Thesleeve 4 also forms a smooth or flush surface with the lateral shoulderof the plug 3 and the adjacent end of the barrel l. r

A rubber plug 5 is fitted tightly in the lower end of the barrel andprovided with a small lengthwise perforation 6 for passage of air. Themouth or outer end 7 of such passage is flared, as shown in Fig. 2, toadapt it to fit closely upon the end of the nipple fr of a bicycle-tire.(See dotted lines, Fig. 2.) The said plug 5 has an enlargedcircumferential shoulder against which the end of the barrel l abuts.

The piston Sis constructed of elastic material, preferably rubber, andhas normally the form of an ordinary tapered bottle cork or stopper. Itis fitted closely and tightly in the end of the piston-tube 2, which endmay be correspondingly flared, as shown. The tapered form of the piston8 prevents it being forced completely into the tube 2 when the pump isoperated, and it tits so tightly as to prevent withdrawal therefrom whenthe piston-tube is being retracted. The piston-head fits snugly in thebarrel 1, so that when pushed inward it prevents passage of air past it,but when retracted its enlarged elastic rim yields sufficiently to allowsuch passage of air. It will be understood that the air enters andpasses between the barrel 1 and piston-v. tube 2 when the latter isretracted, and thus supplies the vacuum createdbetween the plug 5 andpiston 8 at the moment of retraction.

To compensate for wear and insure at all times a proper close t of thepiston inthe tube 2, I employ an expander 9, which is in the form of aconical screw, the same having an enlarged milled head by which it maybe easily gripped and rotated to screw it into the piston propel' orsubsequently adjust it, as may be required.

The head of the piston is made concave, as shown best in Fig. 5, wherebyan annular rim is formed that works in yielding contact with the barrell. I have found this shape particularly advantageous in that the rimyields readily to allow passage of air when the pis- IOO ton isretracted, yet fits the barrel very snugly, but without undue friction,when the piston is forced down.

In practical use the pump is applied as shown in Fig. 1, the plug 5resting directly on the tire-nipple which enters and fits air-tight inits flaring month 7, as shown in Fig. 2. The operator holds the pump asnearly in alinement with the nipple as practicable, and While pressingdown the barrel 1 with one hand he grips and reciprocates thepiston-tube 2 with the other. The length of the pump, which is fromtwenty to twentyfour inches, enables the operator to manipulate itWithout bending low, and the crosssectional area of the same beingcomparatively small the friction is less than inthe ordinary pump.

The pump is light and symmetrical and ymay be carried unobtrusively insuitable elastic hangers beneath and parallel to the upper or top bar ofa bicycle.

The modified form ot' myinvention (shown in Figs. 6 to 9) differs fromthe preferred one mainly in the use of valves in the barrel-plug 10andpiston 1l, the barrel l and piston-tube 2a being constructed asbefore-that is to say, 'the plu g 10 has a ball-valve 12 and the piston11 asimilar one,13. Theplug-valve 12 seats downward and the piston-valve13 seats upward as the latter descends, and it is obvious that thesepositions are reversed in the retractile movement. I propose to employany suitable device for attaching the valves and allowing them tooperate in the required manner. In this instance I show a form of met-alcage 14, (see Fig. 9,) which is conical and perforated at one end andhas flexible inwardly-bent lips orflan ges l5 at the other. It isapparent that the valves Will seat in the conical end of this cage orholder 14, so as to prevent passage of air, but the anges 15 offer noobstruction there to. The cage 14 may be secured in the plug 10 bycement or by other mechanical means, and it may be soldered in the metalexpander. The latter has necessarily a longitudinal perforation 16, Fig.7, and the piston-tube plug 17, Fig. 6, has also a longitudinal passagefor admission of air.

In Fig. 8 I show the barrel-plug 10 provided With a metal tube orbushing 18, which lines its central passage and is slightly iared at itsouter end. This tube may be employed when required to prevent thepassage from closing by compression on the tire-nipple cc.

What I claim is- 1. A bicycle hand -pump comprising an elongated barreland a sliding piston-tube, an elastic plug secured in the outer end ofsaid tubeand having a shoulder, and the rubber sleeve surrounding thetube adjacent to such shoulder, and forming a surface which is flush orsmooth with the barrel and said shoulder of the plug, as shown anddescribed'.

2. In apump, thecombination with an elastic piston, of a conical screwwhich is inserted in the head of the same and serves to expand it asshown and described.

3. A bicycle-pump comprisingan elongated barrel, and piston-tube,perforated end plugs for said barrel and piston-tube, an elastic pistonsecured in the latter, a perforated expander applied to the piston, andvalves held in the barrel-plug and expander and adapted to alternatelyopen and yclose the passages, as shown and described.

In testimony whereof I have signed my name to this specification in thepresence of two subscribing Witnesses.

JOHN H. ROBINSON.

Witnesses:

AMos W. HART, SoLoN C. KEMoN.

